1. Field of the Invention
The present invention relates to ink. In particular, the present invention relates to an ink suitable for ink-jet recording in which recording is performed on a recording material by ejecting the ink from an orifice in response to recording signals, as well as to an ink-jet recording method, an ink cartridge, a recording unit, an ink set, and an ink-jet recording apparatus.
2. Description of the Related Art
In the ink-jet recording method, recording is performed by adhering ejected ink droplets to a recording material, for example, paper. In particular, according to the ink-jet recording method, the printing of color images can be performed with ease. Liquid droplets are generated by bubbles that are generated in the ink due to the application of thermal energy using an electrothermal transducer as the ejection energy supply device, as disclosed in Japanese Patent Publication No. 61-59911, Japanese Patent Publication No. 61-59912, and Japanese Patent Publication No. 61-59914. In recent years, regarding ink-jet recording apparatuses, costs have been reduced and printing speeds have been improved, and regarding ink-jet recording images, image qualities have been further improved. In addition, color ink-jet recordings have been used for various purposes.
In color recordings made by an ink-jet recording method, water-based inks, in which dyes having various color tones are dissolved into the water-soluble media, may, for example, be used. These inks preferably satisfy, at high levels, at least the following properties (1) to (10), which are required of ink-jet recordings.    (1) The recording has a sufficient image density.    (2) The recording is likely to dry on a recording material.    (3) There is no blurring in the recorded image.    (4) The recorded image does not bleed due to contact with water, alcohol, etc.    (5) The recorded image is superior in light resistance.    (6) Plugging in the nozzle tip does not occur.    (7) Problems of fading of the recorded image, etc., do not occur during continuous printing or at the start of recording after a long term of standing.    (8) The ink is stable during preservation.    (9) No problems are caused by contact with members constituting the recording device during use.    (10) The recording is superior in heat resistance and does not adversely affect the thermal energy generation element.
Among the inks of various color tones used for the color recordings, azo dyes and xanthene dyes which can produce magenta inks having superior color tones are the typical dyes used for a water-based ink having a magenta color. The aforementioned magenta ink having superior color tone makes the realization of an ink-jet image having a high quality comparable to a silver halide photograph possible. In recent years, however, regarding ink-jet recording images, not only high image quality, but also high durability of the formed image has been required.